Add support for serde to the Primes struct, hidden behind a feature. (#41)

* impl serde::serialize when the serde feature is on

* Add serde support for deserialization with serde_arrays

* Document the serde feature in lib.rs, README.md and Cargo.toml

* Document serde feature in changelog

Author: JSorngard

CHANGELOG.md

@@ -1,11 +1,14 @@
 This file contains the changes to the crate since version 0.4.8.
 
+# 0.8.2
+
+ - Add the `serde` feature that derives the `Serialize` and `Deserialize` traits from `serde` for the `Primes` struct.
+
 # 0.8.1
 
  - Added a crate feature flag badge to the docs.
  - Mention what can be done with the crate clearer in the description.
 
-
 # 0.8.0
 
 ## Breaking changes

Cargo.toml

@@ -9,13 +9,19 @@ categories = ["mathematics", "no-std", "no-std::no-alloc", "algorithms"]
 description = "Work with prime numbers in const contexts. Prime generation, primality testing, prime counting, and more."
 repository = "https://github.com/JSorngard/const-primes/"
 
+[dependencies]
+serde = { version = "1.0", default-features = false, features = ["derive"], optional = true}
+serde_arrays = {version = "0.1.0", optional = true}
+
 [dev-dependencies]
 criterion = { version = "0.5", features = ["html_reports"] }
 rand = "0.8"
 
 [features]
 # Implements the `Error` trait from the standard library for the error types.
 std = []
+# Derives the `Serialize` and `Deserialize` traits from [`serde`](https://crates.io/crates/serde) for the `Primes` struct.
+serde = ["dep:serde", "dep:serde_arrays"]
 
 # docs.rs-specific configuration. Taken from <https://stackoverflow.com/a/61417700/>.
 [package.metadata.docs.rs]

README.md

@@ -126,7 +126,8 @@ and more!
 
 ## Features
 
-`std`: implements the `Error` trait from the standard library for the error types.
+`std`: implements the `Error` trait from the standard library for the error types.  
+`serde`: derives the `Serialize` and `Deserialize` traits from [`serde`](https://crates.io/crates/serde) for the `Primes` struct.
 
 ## License
 

src/cache/mod.rs

@@ -41,7 +41,10 @@ use crate::{primes, Underlying};
 /// assert_eq!(CACHE.count_primes_leq(1000), None);
 /// ```
 #[derive(Debug, Clone, Copy, Eq, Ord, Hash)]
-pub struct Primes<const N: usize>([Underlying; N]);
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct Primes<const N: usize>(
+    #[cfg_attr(feature = "serde", serde(with = "serde_arrays"))] [Underlying; N],
+);
 
 impl<const N: usize> Primes<N> {
     /// Generates a new instance that contains the first `N` primes.

src/lib.rs

@@ -121,7 +121,8 @@
 //!
 //! # Features
 //!
-//! `std`: implements the `Error` trait from the standard library for the error types.
+//! `std`: implements the [`Error`](std::error::Error) trait from the standard library for the error types.  
+//! `serde`: derives the [`Serialize`](serde::Serialize) and [`Deserialize`](serde::Deserialize) traits from [`serde`](https://docs.rs/serde/latest/serde/) for the [`Primes`] struct.
 
 #![forbid(unsafe_code)]
 #![cfg_attr(not(feature = "std"), no_std)]